SB 275 

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I*. S. DEPARTMENT OF AGRICULTURE. 

BUREAU OF PLANT INDUSTRY— BULLETIN NO. 100, PART 17. 



B. '!". GALLOWAY, I Me/ of Bureau. 



lETHODS OF TESTING THE BUKNING 
QUALITY OF CIGAK TOBACCO. 



WIGHTMAN W. GARNER, 

Scientific Assistant, Plant Breeding Investigations. 



Issued June 9, 1906. 




WASHINGTON: 

GOVERNMENT PRINTING OFFICE, 



1906 
1tonoflr»pt» 



i^p 



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CONTENTS. 



Page. 

Introduction .5 

The smoking test 7 

The effects of the filler, the binder, and the wrapper on the burn of the cigar. 9 

Testing the capacity for holding fire and the evenness of the burn 11 

Testing the burn of cigar-filler tobacco 14 

3 



ILLUSTRATIONS. 



PLATES. 



Page. 

Plate I. Variation in burn of wrappers due to different tillers 14 

II. Variation in burn of iillers due to different wrappers and binders.. 14 

TEXT KICI RES. 

Fig. 1. Apparatus for testing the burning quality of cigars 8 

2. Apparatus for'testing the burning quality of wrapper tobacco 12 

3. Construction of form on which leaf is wrapped for use in apparatus 

shown in figure 2 12 

4 



METHODS OF TESTING THE BURNING 
QUALITY OF CIGAR TOBACCO." 



INTRODUCTION. 

As has been pointed out in previous publications of the Bureau of 
Plant Industry, a systematic effort is being- made to improve the qual- 
ity and yield of the tobacco crop by employing- the latest and most 
approved methods of selection in the old varieties and by creating 
and establishing- new strains possessing to a marked degree those 
characteristics most to be desired in the various classes of tobacco 
which the market demands. This work necessitates the careful test- 
ing of a large number of types, as well as many individual selections 
from each of these types, and for this reason it is very desirable to 
have at our command methods capable of showing with certainty even 
slight "differences in the essential qualities of the various samples to be 
examined. It is our purpose to make a careful study of the subject 
of testing tobacco from a practical standpoint, as well as the relation 
of the chemical composition of the leaf to its good and bad qualities. 

In judging the merits of a cigar tobacco, due regard must be had 
for the particular use for which it is intended, since the finished cigar 
consists of three distinct components — the tiller, the binder, and the 
wrapper — each of which must possess certain characteristics. The 

«In the tobacco breeding experiments conducted by the Plant Breeding Investiga- 
tions of the Bureau of Plant Industry, particular attention is being given to the 
improvement of cigar tobaccos, including specially high-grade wrapper and tiller 
types. In connection with these experiments, which are being conducted by Messrs. 
A. D. Shamel and W. W. Cobey of this Office, it has been found necessary to emu- 
pare the characters of a large number of selected individual plants to determine 
which ones are superior in their important characters. The means and methods 
heretofore used in making such comparative tests were very imperfect, and one 
important preliminary part of the work is to devise special pieces of apparatus which 
will enable accurate tests to be made. The devices described by Dr. Garner in the 
present paper it is believed will greatly facilitate such testing and add to the accuracy 
of the results. The preliminary notes given by Dr. Garner on the influence of 
wrapper, binder, and filler on the "burn" of cigars open up an important field of 
investigation in connection with the testing and breeding of different types of 
tobacco. — Herbert J. Webber, Physiologist in Charge of Plant Breeding Investigations. 



6 TESTING THE BURNING QUALITY OF CIGAR TOBACCO. 

filler must have, above all else, a tine flavor and aroma and a good 
"burn." In the case of the wrapper leaf there are a number of 
requirements to be met, among which are sufficient elasticity, proper 
color, size, and shape, fineness of veins, freedom from objectionable 
flavor and taste, a fiwe "grain," and a good burn. Many of these 
qualities can be determined by simple inspection, without the use of 
any specific tests, while others require special laboratory methods. 
The present article has to do only with the practical methods of testing 
the burn, deferring to a later day a consideration of the chemical 
characteristics of the tobaccos which have been tested. 

There are several elements which go to make a good or bad burn, 
chief of which are the capacity for holding tire, the evenness of the 
burn, the color of the ash and its firmness, the coaling or carboniza- 
tion, and the " puckering " of the leaf immediately in advance of the 
burning zone of the cigar. The final test of any cigar tobacco must, 
of course, rest in the smoking of the manufactured cigar, but, while 
this gives a direct means of determining the character of the ash, it 
does not furnish accurate information as to the evenness of the burn 
or the fire-holding capacity of any one of the components of the cigar 
except with reference to the other two particular components used in 
the experiment. This is particularly true of the wrapper, as was 
shown by special experiments carried out to observe the effect of 
using different fillers and binders with the same wrapper. The result 
of these experiments will be more fully discussed below. Again, it 
should be remembered, in this connection, that cigars made by the 
same workman and from the same lot of tobacco often vary widely in 
their burn owing to the impossibility- of avoiding unevenness in the 
tiller, and this source <>!' error can only he eliminated by several times 
repeating the experiment. It is evident, therefore, that, in order to 
get reliable data concerning the relative merits of different wrappers 
with respect to their burning qualities, the cigar test must be supple- 
mented by some other method capable of giving sharp distinctions as to 
the fire-holding capacity and evenness of burn. 

A method which has long been in use is to ignite the leaf by means 
of a lighted cigar or a slow-burning match devised by Nessler," and 
note the number of seconds during which it continues to glow. The 
mean of several tests is taken as a measure of the capacity for holding 
fire; but the variation in the results obtained, even upon a single leaf, 
is so great that little reliance can be placed upon the figures except in 
a very general way. In this method no account is taken of the area 
of the leaf burned, and the wide differences obtained on a single leaf 
are due principal^ to the fact that frequently the ignited zone soon 
ceases to glow except for one or more very small streamers, which 

«Landw. Vers. Stat. ; XI, 399. 



THE SMOKING TEST. 7 

continue to burn for u much longer period, thereby giving results 
altogether out of proportion to the true burning qualities of the 
tobacco in question. Another serious objection to the method is found 
in the interference of the veins of the leaf; for it seldom happens 
that the glow can cross these veins except around the outer edges of 
the leaf, while in the cigar the veins always run longitudinally and 
so do not interfere with the burn. 

The rational procedure would seem to be to test the burn of the 
leaf when wrapped in some such form as is actually found on the cigar, 
but without the use of binder or tiller. We have devised a method of 
this kind in which the leaf, after being properly wrapped and dried, is 
burned with the aid of a slow current of air. The current of air com- 
pensates in a measure for the absence of the tiller and binder, while its 
use obviates the unavoidable irregularities of the latter. A detailed 
description of the apparatus used and the method of carrying out the 
operation will be found on page 11. This test, combined with the 
smoking of the cigar, has enabled us to accurately classify a large 
number of samples of wrapper leaf with respect to their burning 
qualities. 

THE SMOKING TEST. 

It is evident that no two persons would smoke a cigar in exactly the 
same way, nor would the same individual smoke two cigars under 
exactly similar conditions. It is necessaiw, therefore, to use some 
means of smoking the cigars artificially in order to eliminate the per- 
sonal equation and secure uniformity of conditions. Dr. E. II. Jen- 
kins, in the Annual Keport of the Connecticut Agricultural Experi- 
ment Station for 1892, has described an apparatus for smoking cigars 
which was devised by Mr. S. L. Penfield, of Yale University. The 
" pull 51 on the cigar is secured by means of an aspirator which is tilled 
b} T a continuous inflow of water and emptied at regular intervals by a 
siphon. We have modified this apparatus in a number of details in 
order to adapt it to our needs, and we give herewith a description of 
the form and dimensions which we have finally adopted for use in 
our investigations. In this apparatus as many as four cigars may be 
smoked simultaneously, while held in such a position that they may 
be readily compared throughout the operation. 

By reference to the accompanying illustration (tig. 1) it will be seen 
that the holders (a, I, c, and d) for the cigars are so arranged that 
they all lie in the same vertical plane, each one 2 inches above and 
having its horizontal arm 2 inches shorter than the next lower. A 
screen with a white covering is placed immediately in the rear of the 
holders to serve as a background, thereby facilitating observation of 
the character of the ash. Between the flask bearing the holders and 
the aspirator and connected with these by means of glass tubing is a 



8 TESTING THE BURNING QUALITY OF CIGAR TOBACCO. 

check valve consisting of a T-tube (e), the lower arm of which dips 
beneath the surface of the water in a suitable vessel (/), thus prevent- 
ing a backward draft through the cigars while the aspirator is filling. 
The smoke which escapes through this valve has a very disagreeable 
odor; hence, it is well to use a bottle fitted with a stopper with two 
holes, through one of which passes the lower arm of the T-tube {</). 
while through the other passes one end of a long tube (//), which car- 
ries away the obnoxious fumes. The aspirator consists of a glass cyl- 
inder (/). the upper end of which is fitted with a rubber stopper 




Fig. 1.— Apparatus for testing the burning quality of cigars: ". '■, c, <i. holders for cigars; c, T-tube, 
the lower arm (if which, g, dips beneath surface of water in/; h, h, tube for leading away tobacco 
smoke; i. aspirator; /.-. lube leading to water supply; o,p, long and short arms of siphon: I, tube 
connecting cigar holders with aspirator; m, tube, with bulb, attached to long arm of siphon; it, 
flask carrying the cigar holders. 

containing two holes through which pass tubes leading to the water sup- 
ply (k) and to the flask carrying the cigar holders (/), respectively. 
The lower end of the cylinder is closed with a rubber stopper bearing 
the small arm of the siphon (->). The tube furnishing the water sup- 
ply is connected with a reservoir provided with a constant-level attach- 
ment, To the lower end of the small arm of the siphon is attached a 
glass tube (m) bearing a small bulb which materially assists in break- 
ing the flow of the water at the moment the aspirator is emptied. The 
tubing connecting the parts of the apparatus should not be less than 



EFFECTS OF FILLER, BINDER, AND WRAPPER ON BURN. 9 

6 to 8 ram. internal diameter; otherwise the tubes will frequently become 
clogged by the, condensation products of the smoke. The container 
for the cigar holders (n) is filled about two-thirds full with dilute sul- 
phuric aeid, which serves as an acid wash for the smoke, retaining the 
organic bases and thereby further helping to prevent the choking up 
of the machine. The lower ends of all the cigar holders should, of 
course, extend to exactly the same depth below the surface of the 
aeid. 

In the machine which we now have in operation, the relation between 
the short arm of the siphon and the internal diameter of the aspirator 
is such that the volume of water delivered at each emptying of the 
latter is 600 e.c. This corresponds to an actual capacity of about 450 
e.e. for the aspirator, the difference, of course, representing the volume 
of water entering the aspirator from the supply pipe while the siphon 
is in action. The rate of inflow from the supply tank is approximately 
900 c. c. per minute. The internal diameter of the long arm of the 
siphon is 8 mm., while that of the short arm is 25 mm. The entire 
length of the long arm of the siphon exceeds that of the short arm by 
40 em. An apparatus of the above-mentioned dimensions will smoke 
four cigars of the Perfecto type, ±1 inches in length, in about thirty 
minutes, a rate which is probably somewhat above that of the average 
smoker. The pull on the cigar occurs at intervals of thirty seconds 
and continues for a period of ten seconds. The frequency of the pull 
is controlled by the rate of inflow of the water from the supply tank, 
while its duration is governed principally by the relation between the 
diameter of the small arm of the siphon and the volume of the 
aspirator. 

THE EFFECTS OF THE FILLER, THE BINDER, AND THE WRAPPER 
ON THE BURN OF THE CIGAR. 

As preliminary to the use of the cigar test in examining wrapper 
leaf, a series of experiments was carried out to determine the relative 
effects of the three components of the cigar on the burn. For this 
purpose a number of cigars were made by an expert w T orkman, using 
four different types of wrapper on each of four different types of 
tiller. In a portion of the cigars the binder used was taken from the 
same leaf as the wrapper, while in the remainder a sample of Connecti- 
cut Broadleaf tobacco was employed for this purpose. These cigars 
were smoked in the above-described apparatus under conditions as 
nearly uniform as could be obtained, and the evenness of the burn and 
the character of the ash were carefully noted. 

With reference to the evenness of the burn, markedly different 
results were obtained when wrappers taken from the same sample were 
smoked on different types of tiller. A typical case of this kind is shown 
in Plate I. The twelve cigrars shown were all made from the same 



10 TESTING THE BURNING QUALITY OF CIGAR TOBACCO. 

sample of wrapper, and in each case the binder was taken from the 
same leaf as the wrapper. In the first group (A), a sample of filler 
grown in Texas from Cuban seed was used; in the second group (B), a 
heavy filler grown in Ohio from domestic seed; in the third group (C), 
a tiller grown in South Carolina from Cuban seed; in the fourth group 
(D), an imported Cuban filler. The wrapper used on these cigars was 
a type of Sumatra tobacco grown in Connecticut and had a very good 
burn. The Texas and imported Cuban fillers were known to have an 
excellent burn, while the South Carolina tiller was markedly inferior 
in this respect and the Ohio tiller intermediate in burning qualities. It 
will be seen that this sample of wrapper burned quite evenly when 
used with the imported Cuban and Texas fillers, while with the Ohio 
and especially the South Carolina tillers the burn was decidedly uneven. 

On the other hand, the effect of using different types of wrapper on 
the evenness of burn of any one type of tiller was less marked (see PI. 
11, A, B, and C; also PI. I, D). The tiller used in this experiment was 
the imported Cuban, while the wrappers were taken from four differ- 
ent types of Sumatra tobacco grown in Connectieut. Of these four 
types of wrappers, that shown in Plate I, group D, had the best burn 
and the one shown in Plate II, group C, the poorest, although little 
difference could be seen between the two when smoked on the Cuban 
tiller. The use of different binders did not cause any marked differ- 
ences in the evenness of the burn, as is shown in Plate II, groups C 
and D. The cigars used in this experiment were all made from the 
same wrapper and the same tiller, while in group D a sample of Con- 
necticut Broadleaf tobacco was used as the binder, and in group C the 
binder was taken from the same leaf as the wrapper. 

Another important factor in determining the evenness of the burn is 
the proper balancing of the component parts of the cigar. It was 
found, for example, that a very light" wrapper will not give good 
results on a heavy tiller, even though both of these may in themselves 
possess a good burn. It will readily be seen that a very thin wrapper 
which burns readily and very rapidly will, when placed on a heavy, 
slow-burning tiller, tend to burn in advance of the latter, and the effect 
will generally he an uneven burn. The same result is obtained when 
any cigar is smoked very rapidly, for the reason that the ox} T gen of 
the air has freer access to the outer edges of the burning zone and 
under the added stimulus it rarely happens that a cigar will burn 
evenly. 

As regards the character of the ash, the wrapper and the binder are 
relatively of much more significance. It was found, it is true, that 
some tillers give an ash lacking in compactness and liable to split 
asunder, but the tendency to flake seems to be controlled almost entirely 

«The terms //';//// and heavy as used in this connection refer to the body or thick- 
ness of the leaf, which largely controls the rapidity of the burn. 



EIRE-HOLDING CAPACITY AND EVENNESS OF BURN. 11 

by the character of the wrapper and binder. Furthermore, this lack 
of cohesion in the ash of a wrapper may be largely overcome by the 
use of a good binder. As to the color of the ash, a binder having a 
good burn will impart to the ash of the wrapper a lighter tint and a 
more uniform color. The general results of these experiments may 
be summarized as follows: 

(1) In order to secure a good burn, due consideration should be given 
to the proper balancing of the components of the cigar; that is, a heavy 
tiller should be wrapped with a comparatively heavy wrapper, while a 
light -bodied tiller requires a light-bodied wrapper. 

(2) Of the three components of the cigar, the tiller exerts the strongest 
influence on the evenness of the burn. 

(3) The influence of the wrapper and binder is shown most strongly 
on the character of the ash, and the binder very materially influences 
the ash of the wrapper in this respect. 

TESTING THE CAPACITY FOR HOLDING FIRE AND THE 
EVENNESS OF THE BURN. 

The factors of holding tire and of burning evenly are of prime 
importance in judging the burn of tobacco, and any sample found 
markedly deficient in these points may be rejected without applying 
any further test. As has been previously stated, the old method of 
measuring the lire-holding capacity is likely to lead to erroneous con- 
clusions, while there has heretofore been no direct method of deter- 
mining the evenness of the burn of wrapper leaf. In the process 
which we have used for testing wrapper tobacco with regard to these 
elements of the burn, the area of the leaf consumed, rather than the 
time elapsing before the glow is extinguished, is measured. 

The form of the apparatus used in this method will be understood 
by reference to the accompanying illustration (tig. 2). The essential 
feature is the form on which the leaf is wrapped, consisting of a col- 
lapsible wooden tube, one end of which tits into a glass tube of the 
same diameter. This latter is in turn connected with a second glass 
tube through which is drawn a current of air. The best material for 
making the wooden form is well-seasoned cherry with a straight grain, 
but ash has also been found to answer the purpose very well. From the 
wood selected is made a cylinder 5 inches in length, f inch in diameter 
.at one end, and tapering slightly to the other end (see tig. 3). In the 
larger end of the cylinder a f-inch hole is bored to a depth of 3f inches, 
and the shell thus formed is separated into six equal segments by saw- 
ing to a depth of 3i inches. The smaller end is cut down for a dis- 
tance of H inches, so as to tit snugly into the glass tube. The shoulder 
thus formed should correspond in depth to the thickness of the wall of 
the glass tube. Near the larger end of the form a groove (c) is cut, 
into which is fitted a rubber band. The plug (d) has a diameter such 



12 



TESTING THE BURNING QUALITY OF CIGAR TOBACCO. 



that when inserted in the end of the form the latter is expanded to its 
original size. The receiver (a) for the form is made by drawing out 




jr IG 2.— Apparatus for testing the burning quality of wrapper tobacco: o, entrance of air current: b, 
wrapper to be tested: c, e, glass tube to which the form bearing the wrapper is attached by means 
of the cork, to; d, d.large glass tube fitted with corl&, n, //. through which passes c, c; f, flask 

containing water; o, small glass lube dipping beneath the surface of the water in /; ji, short glass 
tube leading from/; /<. pump by means of which the current of air is secured; , , , and g, </, rubber 
tubing connecting parts of apparatus; t, water tap; i. outflow of water. 

one end of a short piece of thick-walled glass tubing. All of the above 
dimensions are based on tubing having an internal diameter of 14 mm. 
(9 16 inch) and an external diameter of 18 mm. (11 16 inch). The 
small end of the re- 



ceiver is fitted with 
a soft cork (A), by 
means of which it is 
connected with the 
other portion of the 
apparatus. 

From the leaf to 
be tested, which 
should be quite 
damp, the wrapper 
is cut into a form 
quite similar to that 
used for cigars, and 
the same rules are observed as regards the cutting of right-handed and 
left-handed wrappers, etc. Beginning at the outer end the wrapper is 




Fig. 3. — Construction of form on which leaf is wrapped for use in 
apparatus shown in figure 2: a, glass tube for receiving the form; b, 
cork by which receiver (a) is connected with remainder of apparatus 
shown in figure 2; c, rubber band for collapsing the form; d, plug 
for expanding the form: (. form on which leaf is wrapped. 



FIRE-HOLDING CAPACITY AND EVENNESS OF BURN. 13 

rolled quite tightly, first on the form and then on the glass. At the 
beginning of the process of rolling, the extreme outer corner of the 
base of the wrapper is attached to the overlapping portion with a bit 
of cigar paste, and at the end of the operation the tip of the wrapper 
is attached to the receiver by the same means. A number of samples 
to be tested are thus wrapped on the forms and set aside until they 
have dried out properly. The plug in the end of the form is then 
withdrawn and the rubber band causes the walls of the latter to col- 
lapse, so that it can be easily withdrawn from the receiver. This 
leaves the sample of wrapper securely attached to the glass tube, 
and in exactly the same form it would have on a cigar. The tube 
carrying the sample to be tested is connected with the remainder of 
the apparatus, shown in figure 2, the construction of which will be 
understood without further explanation. The current of air is fur- 
nished by means of an ordinary filter pump, and its rate can be con- 
trolled with sufficient accuracy by measuring the flow of water through 
the pump. The end of the wrapper is ignited with a tlat gas flame, 
and the evenness of the burn and the portion consumed before it ceases 
to glow are carefully noted. Our method of recording the results is 
to grade each sample on a scale of ten, both with reference to the 
evenness of the burn and the fire-holding capacity. Of course, stand- 
ards in these tests are purely arbitrary, as the results are only intended 
to be comparative. Under the conditions laid down for the experi- 
ment, wrappers having markedly good burning qualities will burn up 
completely and evenh r with only one lighting, and these are given a 
grade of 10. 

For the purpose of comparing the results obtained by this method 
with those given by the cigar test with reference to the evenness of the 
burn, a number of leaves were selected from different types of wrap- 
per tobacco. One half of each leaf was used for wrapping a cigar and 
the second half was wrapped on the form for testing, as has just been 
described. There was a decided lack of agreement in the results 
obtained fry the two methods when onty one t}^pe of filler was used in 
making the cigars. It was found that frequently a wrapper that 
graded only 5 or 6 on a scale of 10 in what may be called the " form 
test " would burn quite evenly on the cigar, whereas another wrapper 
grading as high as 9 in this test would show an uneven burn on the 
cigar. A good illustration of this point is found in a wrapper which. 
was scored 10, 9, 10, respectively, in three experiments with the form 
test and gave a fire-holding capacity of 65 seconds by the old method 
of Nessler. On one type of filler this wrapper gave a very uneven 
burn, but when smoked on a lighter filler the burn was perfectly satis- 
factory. These results, then, seem to emphasize the fact that, although 
the final judgment as to the burning qualities of a wrapper which has 
shown up well in the preliminary tests must be based on the smoking 



14 TESTING THE BURNING QUALITY OF CIGAR TOBACCO. 

of the cigar, great care must be exercised to avoid the sources of- error 
in this test which have been previously discussed. The test should not 
only be repeated with a single type of filler to avoid the effects of any 
possible unevenness or other imperfections in the manufacture of the 
cigars, but at least two different types of filler should be used, one of 
these being- heavy and the other light in the sense in which these terms 
fire used here. 

TESTING THE BURN OF CIGAR-FILLER TOBACCO. 

Testing the burn of a filler is a much simpler problem than is the 
case with a wrapper. The principal elements of the burn are the 
evenness and the capacity for holding fire, and the character of the ash 
is unimportant, except that it should be compact. The evenness of 
the burn and the fire-holding capacity are best determined by using 
the cigar test. In the case of filler tobacco the capacity for holding 
fire thus refers simpl}' to the length of time the cigar will continue to 
burn after being lighted without being puffed by the smoker. The 
effects of the binder and wrapper on the burn may be avoided by 
making the entire cigar from the filler leaf to be tested. Another 
decided advantage in making the whole cigar from the same tobacco 
is that the aroma, which is so important in the filler, can also be tested 
at the same time. In determining the fire-holding capacity it is only 
necessary to light the cigar and test it at gradually increasing intervals 
of time to tind whether it has ceased to burn. It is, however, desir- 
able to test the tire-holding capacity and the evenness of the burn on 
separate cigars if sufficient material is at hand for this purpose. 



O 



Bui. 100, Pt. IV, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate I. 




Variation in Burn of Wrappers Due to Different Fillers: A, Filler Grown 
in Texas from Cuban Seed; B, Filler Grown in Ohio from Domestic Seed; 
C, Filler Grown in South Carolina from Cuban Seed; D, an Imported 
Cuban Filler. 



The same samp 



if Sumatra wrapper was used throughout and the binder was taken from the 
same leaf as the wrapper in each case. 



Bui. 100, Pt. IV, Bureau of Plant Industry, U. S. Dept. of Agricultur 



Plate II. 




Variation in Burn of Fillers Due to Different Wrappers and Binders: A, B, C, 
Three Different Types of Connecticut-grown Sumatra Wrapper on Same 
Sample of Cuban Filler, Binder Being Same as Wrapper in Each Case; D, Same 
Wrapper and Filler as C, but Connecticut Broadleaf Used as Binder. 



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